In an operation device of a capacitance type, when an operation surface is operationally touched with a fingertip, a capacitance is changed and whereby the contact operation is detected with. Hence, the comfortable operability of merely lightly touching the operation surface with the fingertip is obtained. However, as a trade-off with the comfortable operability, even if a part of the hand unintentionally contacts the operation surface, the contact operation is detected. For example, as disclosed in Patent Document 1, when a dial (manual operation portion) is disposed in the vicinity of the operation surface, a part of the hand rotationally operating the dial may touch the operation surface, and the contact operation may be detected unintentionally.
To cope with the above problem, in Patent Document 1, when a signal output from the dial is changing, the contact operation on the operation surface is disabled with assuming that an operator's intention is to operate the dial but not to execute the contact operation. Accordingly, even if the operation surface is touched with the hand during the dial operation, various devices can be prevented from being operated on the basis of the contact operation.
However, in the above Patent Document 1, the contact operation is disabled during the output signal from the dial changing, and the contact operation is not disabled by causing the operator to merely pick the dial, and begins to be disabled by the rotational operation. For that reason, there is a risk that the contact operation is detected at the time when the dial is picked for its rotational operation, and the above problem cannot be sufficiently solved.